Towards robust alkane oxidation catalysts: electronic variations in non-heme iron(ii) complexes and their effect in catalytic alkane oxidation
作者:Jason England、Reema Gondhia、Laura Bigorra-Lopez、Allan R. Petersen、Andrew J. P. White、George J. P. Britovsek
DOI:10.1039/b901390c
日期:——
linear and tripodal tetradentate ligands has been prepared. Electron withdrawing and electrondonatingsubstituents in the para position of the pyridine ligands as well as the effect of pyrazine versus pyridine and sulfur or oxygen donors instead of nitrogen donors have been investigated. The electronic effects induced by these substituents influence the strength of the ligand field. UV-vis spectroscopy
However, 1 and 2 have different molecular arrangements and crystal packings, and are isolated in orthorhombic Pbnb and monoclinic C2/c space groups, respectively. 1 remains in a high spin state (S = 2) over all temperatures while 2 undergoes a spin transition around 168 K with a small thermal hysteresis of about 0.4 K (at a temperature scan rate of 1.3 K min–1). This phasetransition, which can also
两个新的单核Fe(II)配合物[Fe(2Me L pz)(NCX)2 ](L = N,N'-二甲基-N,N'-双((吡嗪-2-基)甲基)-1,已经合成了2-乙二胺和X = S(1),BH 3(2)),并通过单晶X射线衍射,磁,光反射率和光磁测量对其进行了表征。它们有相似的汾酒6所提供协调的环境中四齿配体与顺-α构象和两个NCX -共配的顺位。但是,1和2具有不同的分子排列和晶体堆积,并且分别位于正交晶的Pbnb和单斜C 2 / c空间群中。1在所有温度下均保持高自旋状态(S = 2),而2在168 K左右经历自旋转变,并具有约0.4 K的较小热滞(在1.3 K min的温度扫描速率下–1)。这种相变也可以通过样品颜色的相关显着变化进行光学检测,发生在两个结构特征相之间,在高温和低温下,它们分别在高自旋和低自旋状态下表现出Fe(II)配合物。这两种状态之间的可逆光开关也已在低温下使用良好分开的波长辐照进行了确认。